Sensus 122 Series User manual
*This document replaces RM-1329-R7
IN-G-REG-13-29-0814-03-A*
Model 122 Regulators
Installation and Maintenance Instructions
Introduction
The Model 122 Regulator illustrates a combination of capacity,
performance and value. The streamline body passages provide
large capacity. Internal control is standard with external control
also available. The 122 has a fast speed of response, yet is stable
in operation. Soft seats ensure positive tight shutoff. Orices are
replaceable. Springs are color coded.
And it is also available as a zero governor or atmospheric
regulator, a differential regulator and a relief valve or back-
pressure regulator.
Installation
1. Examine the regulator for shipping damage.
2. Check nameplate data. Be sure regulator conforms with what
was ordered.
3. Inside of regulator and piping must be clean and free of dirt.
Remove all dirt and debris before installing regulator. Failure
to remove dirt/debris could result in regulator damage
or trouble.
4. Remove all shipping screens and covers from the regulator.
Do not let dirt get inside the regulator.
5. Install the regulator.
Make sure the inlet and outlet are correctly connected. High
pressure connects to the inlet. The ow arrow must point
downstream.
6. Screwed connections must conform with good piping practice
free of excess thread engagement per ANSI B2.1. Apply pipe
joint compound to male threads only.
7. The model 122 regulator is usually installed right side-up
as shown on the Typical installation drawing (See Page 3).
It may, however, be installed upside down. Although, when
inverted it may be necessary to readjust the set-point.
Caution: Do not install sideways.
The diaphragm should be horizontal.
8. On indoor installations requiring venting outdoors, run the vent
piping as short and indirect as possible with minimum bends
and elbows. Use the same size pipe as the vent connections
on the regulator. With natural gas, or any other hazardous
gas, vent to a safe place outdoors in case gas should
accidentally be discharged. Screen and protect the outdoor
opening to guard against water, ice, dirt, debris or insects.
This item only applies to regulators requiring a control line. It
does not apply to 122 Regulators with internal control. Install
the control line. Connect it into the outlet piping at least 5 pipe
diameters downstream from the regulator.
Caution:
a. On backpressure regulators and relief valves with external
control, the control line connects into the inlet piping.
b. Do not install any automatic shutoff device that closes
completely between the regulator and the control line
connection into the piping.
To avoid excessive turbulence, the connection should be clean
and smooth on the inside and be located in straight pipe clear
of valves and ttings. Keep the inside of the control line clean
and protect it from corrosion. Pitch it away from the regulator
and avoid moisture pockets. It must be strong (¼" or larger
steel tubing or pipe is preferred). It must be well protected
against breakage (remember, regulators open wide if the
control breaks).
9. Make sure the regulator is correctly connected and adequately
supported and pipe joints are tight.
Start-Up
A. The inlet and outlet shutoff valves should both be closed. If a
by-pass is used, the bypass valve should also be closed.
B. Note the set-point (set-point is the outlet pressure the
regulator is adjusted to deliver). Regulator is factory adjusted
to the set-point specied on the order.
Caution:
This caution applies where the piping downstream of the
outlet shutoff valve is pressured. That pressure must not
exceed the regulator set-point by more than 2 psi (see
“Maximum Emergency Pressures”, Page 11).
C. Slowly and carefully open the inlet shutoff valve just enough to
allow inlet pressure to build up slowly in the regulator until it
is fully pressured.
Caution:
During start-up a pressure gauge must be used on the
regulator outlet pressure and carefully watched. While inlet
pressure builds up, outlet pressure must not exceed set-point
by more than 1 psi. If outlet pressure begins to exceed
set-point by more than 1 psi, close the inlet shutoff valve.
This indicates the regulator is not closing properly. Check and
make necessary corrections before proceeding with start-up.
If regulator outlet pressure exceeds set-point by more than
2 psi, refer to “Maximum Emergency Pressures”, Page 11 for
instructions.
D. Check installation for leaks.
E. Slowly open the outlet shutoff valve to allow a small ow
(approximately 250 SCFH). Make sure the ow of gas does
not create a hazard.
NOTE: If piping downstream of outlet shutoff valve is
pressurized, see “Caution” under B.
F. With gas owing, check for correct inlet and outlet pressures.
It may be necessary to further open the inlet shutoff valve to
maintain full inlet pressure.
G. Make sure the regulator closes tight (tight lock-up). To do this,
reduce ow to zero by slowly closing the outlet shutoff valve.
Outlet pressure should not exceed set-point by more than
3" w.c.
H. Fully open inlet and outlet shutoff valves slowly and carefully.
Watch pressure gauges.
I. Complete start-up by making sure there are no leaks.
2
Model 122 Regulators Installation and Maintenance Instructions
NOTE
The Model 122 Regulator can be used for owing temperatures
from -20°F. to 150°F.
The Model 122 Regulator is not recommended for buried service.
(See Pages 5–10)
The 122 is factory as specied on the order. To change the
set-point, readjust as follows:
1. Remove top cap 1.
2. Adjust set-point with adjustment button 3or 6. Turn
clockwise to increase and counterclockwise to decrease
the outlet pressure.
NOTE:
a. Only make this adjustment when gas is actually
owing through the regulator. The ow should be small
(approximately 250 SCFH). Do not adjust when the
regulator is closed and there is no ow.
b. Do not increase the set-point beyond the upper limit of
the outlet pressure range for the spring 9(refer to
spring tables, Page 3).
c. Always check the outlet pressure with a pressure gauge
while adjusting the set-point.
3. When adjustment is complete, replace top cap 1. Screw it
securely into place. Leaving it off could cause unstable
regulator operation.
CAUTION
lines ARE NOT used.
(See Pages 5–10)
The outlet pressure ranges of the spring 9are given in the tables
on Page 3. To change the spring:
1. Remove top cap 1.
2. Unscrew and remove adjustment button 3or 6by turning
counterclockwise, and remove spring 9.
3. Insert new spring. Make sure it is positioned correctly at the
bottom before replacing adjustment button 3or 6.
4. Adjust for the desired outlet pressure per previous section
“Set-Point Adjustment.”
5. When adjustment is complete, replace top cap 1. Screw it
securely into place. Leaving it off could result in unstable
regulator operation.
6. New spring range should be marked on regulator. If old spring
range appears on regulator, it should be removed.
CAUTION
NOTE: Before working on the regulator, read the next section
“General Servicing Instructions” and the applicable
servicing instructions.
To shutdown and take the regulator out of service:
1. Carefully close the inlet stop valve.
2. Close the outlet stop valve.
CAUTION
A. Before any disassembly of the regulator make sure it is
completely depressured. Pressure must be fully released from
the inlet, the outlet and the control line connection. Failure to
adequately depressure could result in serious personal injury.
B. Carefully note the location and position of all disassembled
parts to be certain reassembly is correct. Inspect each part
carefully and replace any that are worn or damaged or
otherwise unsatisfactory.
C. Upon completion of servicing, make certain the regulator
installation is entirely free of leaks.
CAUTION
GIM1329-005
3
Model 122 Regulators Installation and Maintenance Instructions
Size
Outlet
Pressure Range Spring Color
Spring
Part Number
Maximum
Inlet Pressure
Nominal
Diaphragm Size
1" and 1¼"
Model 122-8
1½" w.c. to 3½" w.c.
1½" w.c. to 12" w.c.
3½" w.c. to 6½" w.c 1
5" w.c. to 8½" w.c. 1
6" w.c. to 14" w.c. 1
12" w.c. to 28" w.c. 1
1" psi to 2 psi
Blue-Black
Black
Green-Black
Black
Red-Black
Blue-Black
Green-Black
Green
Orange
143-82-021-01 (main spring)
121-41-021-00 (counterspring)
143-82-021-02 (main spring)
121-41-021-00 (counterspring)
143-82-021-00
143-82-021-01
143-82-021-02
143-16-021-05
143-16-021-06
15 psi 8"
½", 2" and 2½"
Model 122-12
1½" w.c. to 3½" w.c.
1½" w.c. to 12" w.c.
3½" w.c. to 6½" w.c. 2
5" w.c. to 8½" w.c. 2
6" w.c. to 14" w.c. 2
12" w.c. to 28" w.c. 2
1" psi to 2 psi
½" psi to 2 psi
Red
Red-Black
Maroon
Red-Black
Red
Blue
Green
Orange
Black
Cadmium
143-16-021-03 (main spring)
121-10-021-50 (counterspring)
121-42-021-00 (main spring)
121-10-021-50 (counterspring)
143-16-021-03
143-16-021-04
143-16-021-05
143-16-021-06
143-16-021-07
143-16-021-08
15 psi 12"
12These Springs are also used on Model 122 Differential Regulators (see below).
{
{
{
{
Size
Outlet
Pressure Range Spring Part Number and Color
Maximum
Inlet Pressure
Nominal
Diaphragm Size
1" and 1¼"
Model 122-8 1" w.c vacuum (-1" w.c.) to + 1½" w.c. 143-82-021-00
121-41-021-00
Red-Black (main spring)
Black (counter spring) 15 psi 8"
½", 2" and 2½"
Model 122-12 1" w.c vacuum (-1" w.c.) to + 1½" w.c. 143-82-021-00
121-10-021-50
Red-Black (main spring)
Red-Black (counter spring) 15 psi 12"
Use 1springs for 1" and 1¼" Model 122-8 Differential Regulators
and 2springs for 1½", 2” and 2½" Model 122-12 Differential
Regulators. For all sizes (¾" through 2½") the Maximum
Diaphragm Pressure Differential is 1 psi, the Maximum Pressure
for the Body is 15 psi and the Maximum Pressure for the
Diaphragm Case is 5 psi.
Size
Relief or Back
Pressure Range Spring Color Part Number
Maximum Body
Inlet Pressure
Nominal
Diaphragm Size
1" and 1¼"
Model 122-8
3" w.c. to 5½" w.c.
5" w.c. to 7½" w.c
6" w.c. to 13" w.c.
10" w.c. to 15" w.c.
12" w.c. to 25" w.c.
18" w.c. to 2 psi
Red-Black
Blue-Black
Green-Black
Blue
Green
Orange
143-82-021-00
143-82-021-01
143-82-021-02
143-16-021-04
143-16-021-05
143-16-021-06
10 psi* 8"
½", 2" and 2½"
Model 122-12
3" w.c. to 5 ½" w.c.
5" w.c. to 7" w.c
6" w.c. to 12" w.c.
12" w.c. to 25" w.c.
20" w.c. to 1¾ psi
Red
Blue
Green
Orange
Black
143-16-021-03
143-16-021-04
143-16-021-05
143-16-021-06
143-16-021-07
10 psi* 12"
*These pressures apply only to External Control Models (refer to Pages 5, 6, 7 or 9). For Internal Control Models the Maximum INLET Pressure is SET-POINT plus 2 psi.
GIM1329-005
Remove Vent Line (If Required)
Top Cap
Adjustment
Outlet
Bypass (If Required)
Vent Cap1
Inlet
Model 122 with Internal Control
1Screened VENT CAP (Model 137) with screen-facing downwards is recommended to minimize
the possibility of water or other foreign matter entering regulator vent.
Remove Vent Line (If Required)
Top Cap
Adjustment
Outlet
Bypass (If Required)
Vent Cap1
Inlet
Model 122 with Internal Control
External Control Line
GIM1329-020
GIM1329-025
GIM1329-030
4
Model 122 Regulators Installation and Maintenance Instructions
1" and 1¼
GIM1329-020
(Internal Control)
GIM1329-030
GIM1329-025
READ “” PAGE 2
1. Remove top cap 1, adjustment 3 and 6 and spring 9.
Mark or measure position of adjustment at start. Use this to
return adjustment to original setting during reassembly.
2. Remove bolts 22 and upper case 21.
3. On standard Regulators and Differential Regulators, remove
bolts 38 and bottom plate 37. Hold valve 15 in upward
position for remaining work.
4. Use a screwdriver in slot in top end of stem 12d or 12t to
prevent stem from turning and loosen and remove nut 11a.
5. Disassemble diaphragm assembly 11.
6. When reassembling, use screwdriver per step 4 above to
prevent stem 12b or 12t from turning while rmly tightening
nut 11a. Excessive turning of stem could strain or damage
seal diaphragm 12b.
7. Rim bolts 22 should be rst made nger tight. Next, insert
spring 9and compress it slightly with adjustment 3or 6, just
enough to force diaphragm assembly 11 fully downwards.
Then tighten screws a little at a time until all are rm and
secure. There must be no leakage around the rim, but
diaphragm 11d must not be crushed, twisted or pinched.
1. Remove bolts 38 and bottom cap 37.
2. For orice 19, remove retaining ring 16a (use Truarc 0200
pliers, Sensus Part No. 1190646), remove split valve holder
16b and remove valve 15.
3. For orice , remove top cap 1and adjustment 3, and
remove spring 9. Mark or measure the position of adjustment
3beforehand and return it to the same place at reassembly.
4. Unscrew orice 19 or using 1⅝" hex socket wrench.
When replacing orice, use a moderate amount of pipe joint
compound on orice threads.
1. Remove bolts 38 and bottom plate 37.
On Back Pressure Regulators and Relief Valves, remove
diaphragm assembly per section “To Service Main Diaphragm
(11d)”, remove bolts 25 and lower case 24, and remove
assemblies 11 and 12 intact and bushing 27.
2. Remove retaining ring 16a. Use Truarc 0200 pliers, Sensus
Part Number 1190646.
3. Remove both halves of valve holder 16b and remove valve 15.
4. Reassemble.
1
2
3
9
21a
11
a
c
f
b
d
24a
25
42
41
43
19 13
17a27 16b17
45
21
22
23
12
e
e
b
a
c
d
24
3235 3837 16a 1415
Standard
Regulator Only;
see Fig. 1 for
others
1
2
3
9
21a
11
a
c
f
b
d
25
19 13
27 16b
45
21
22
23
12
e
e
b
a
c
d
24
3235 3837 16a 1415
Standard
Regulator Only;
see Fig. 1 for
others
Fig.1
ADJUSTMENT 6
and VENT CONNECTION
21b for Differential Regulators,
Atmospheric Regulators
and Zero Governors
1
2
6
9
21b
19 13 16b
32 3837 16a 141517a 17
GIM1329-035
GIM1329-040
5
Model 122 Regulators Installation and Maintenance Instructions
1" and 1¼
GIM1329-035 GIM1329-040
1. Disassemble diaphragm assembly per section “To Service
Main Diaphragm (11d)”.
2. Remove bolts 25 and lower diaphragm case 24.
3. Remove seal washer 12e, spacer 12a and seal diaphragm 12b.
4. During assembly, use screwdriver in slot in top end of stem
12d or 12t while tightening nut 11a. Diaphragms must not be
twisted or strained while regulator reassembly is completed.
1. Remove seal diaphragm 12b per Section “To Service Seal
Diaphragm (12b)” and remove bushing 41. Reinstall seal
diaphragm 12b so it covers and blocks the hole for bushing
41, and reassemble.
2. On Back Pressure Regulators and Relief Valves, install
washer 12c and seal diaphragm 12b in place of gasket 26,
install spacer 12a in place of 12s and reassemble.
3. Remove plug 24a and install external control line.
1. A new body, ILL. No. 35 (with internal control tube 43),
is required for standard, differential and atmospheric
regulators and zero governors, installation requires complete
disassembly per previous sections except that assemblies 11
and 12 remain intact. Install bushing 41 and O-ring 42.
2. On back pressure regulators and relief valves, add gasket 26
in place of seal diaphragm 12b, add spacer 12s in place of
spacer 12a and remove 12c as shown, and reassemble. To
disassemble follow section “To Service Seal Diaphragm (12b) .”
3. Install plug 24a.
(Internal Control)
Illustration
Number Description
Part
Number
1 Top Cap 143-16-005-00
2 O-ring 951357
3 Adjustment Button 143-16-009-00
6 Adjustment Button 121-10-309-50
9 Spring, See Tables, Pages 3–4
11a Nut 908158
11b Bottom Spring Button 121-10-022-50
11c Diaphragm Pan 121-10-017-50
11d Diaphragm, Buna-N, Std. 121-10-150-50
11f Grip Washer 121-41-178-00
12a Spacer 121-41-079-00
12b Seal Diaphragm, Buna-N. Std. 121-41-064-00
12c Clamp Washer 121-41-010-00
12d Stem, Stainless 121-41-016-02
12e Seal Washer 107-62-358-01
12s Spacer, Std., Stainless 121-41-079-01
12t Stem, Stainless 121-41-016-03
13 O-ring, ⅜" x ½" 934007
1
2
3
9
21
23
24
25
26
45
11
f
b
a
c
d
37 20
14a
27 3235 16a 131538 16b
21a
22
12
e
e
s
t
24a
14b
1
2
3
9
21
23
24
25
45
11
f
b
a
c
d
37 20
14b
27 3235 16a 131538 16b
21a
22
14a
12
e
e
b
a
c
t
6
(Continued)
Illustration
Number Description
Part
Number
13 O-ring, Viton, ⅜" x ½" 902418
14 Wave Washer 905479
14a Washer Retainer 121-16-103-50
14b Spacer Washer, Poly-U, Std. 121-16-102-52
15 Molded Valve, Buna-N, Std. 121-10-311-50
16a Retaining Ring, (5100-75H) 904447
16b Valve Holder, Split, Stainless 121-16-130-51
17 Counterspring, See Table, Pages 3–4
17a Spring Guide 121-42-018-00
19 Orice, 1¼" dia., brass, Std. 143-16-023-03
20 Orice, 1¼" dia., brass, Std. 121-10-023-50
21a Vent Valve Assy 143-16-526-01
26 Gasket 121-41-063-00
32 Tetreaseal (or O-ring), 2⅜" x 2½" 904081
41 Bushing 121-41-091-00
42 O-ring, ¼" x ⅜", Buna-N 934005
43 Control Tube 121-41-015-01
45
Travel Indicator
Repair Kit — consisting of Main and Seal
Diaphragms, Seal Washers, Molded Valve
with Wave Washer and Retaining Ring,
Tetraseals and Gaskets: All internal
control models except Back Pressure or
Relief (Std.)
Back Pressure or Relief with internal
control (Std.)
All external control models (Std.)
091-00-365-63
121-41-598-00
121-41-598-02
121-598-01
Model 122 Regulators Installation and Maintenance Instructions
1. Remove bolts 38 and bottom plate 37.
On Back Pressure Regulators and Relief Valves, remove
diaphragm assembly per section “To Service Main Diaphragm
(11d)”, remove bolts 25 and lower case 24, and remove
assemblies 11 and 12 intact and bushing 27.
2. Remove retaining ring 16a. Use Truarc 0200 pliers, Sensus
Part No.1190646.
3. Remove both halves of valve holder 16b and remove valve 15.
4. Reassemble.
1. Remove top cap 1, adjustment 3or 6and spring 9. Mark or
measure position of adjustment at start. Use this to return
adjustment to original setting during reassembly.
2. Remove bolts 22 and upper case 21.
3. On Standard Regulators and Differential Regulators, remove
bolts 38 and bottom plate 37. Hold valve 15 in upward
position for remaining work.
4. Use a screwdriver in slot in top end of stem 12d or 12t to
prevent stem from turning and loosen and remove nut 11a.
5. Disassemble diaphragm assembly 11.
6. When reassembling, use screwdriver per step 4 above to
prevent stem 12d or 12t from turning while rmly tightening
nut 11a. Excessive turning of stem could strain or damage
seal diaphragm 12b. Emery surface of grip washers
should face against both sides of diaphragm 11d.
7. Make rim bolts 22 nger-tight. Next, insert spring 9 and
compress it slightly with adjustments 3or 6, just enough to
force diaphragm assembly 11 fully downwards. Then tighten
screws 22 carefully and evenly, alternately tightening opposite
screws a little at a time until all are rm and secure. There
must be no leakage around the rim, but diaphragm 11d must
not be crushed, twisted or pinched.
1. Remove bolts 38 and bottom plate 37.
2. Remove valve 15 per section “To Service Valve (15)”. (Does
not apply to back Pressure Regulators and Relief Valves.)
3. Remove main diaphragm 11d per section “To Service Main
Diaphragm (11d)”, remove bolts 25 and lower case 24, and
remove assembly 12 and bushing 27.
4. Remove retaining ring 19a. Use Truarc 0600 pliers, Sensus
Part Number 1190648.
5. Remove orice 19.
6. On assembly be sure retaining ring 19a is fully seated in the
groove all the way around the orice.
Also, note the bevel on the inside edge of 19a. The bevel
must face toward the knife-edge of the orice.
GIM1329-045
GIM1329-050
GIM1329-055
GIM1329-060
7
Model 122 Regulators Installation and Maintenance Instructions
GIM1329-045
GIM1329-055
GIM1329-060
(Internal Control)
GIM1329-050
½
READ “” PAGE 2
1
2
3
921b
43
1
2
3
9
Standard
Regulator Only;
see Fig. 1 for
others
45
21
22
23
24
25
26
27
18
17
1935 16b13
3732 19a38 16a 1517a
11
a
c
f
b
d
24a
21a
12
a
b
e
a
c
d
42
11f
40
14
2" and 2½"
Sizes Only;
see Fig. 2 for
1½" size 18
1935 16b13
3732 19a38 16a 1415
1
2
3
9
Standard
Regulator Only;
see Fig. 1 for
others
11
a
c
f
b
d
12
a
b
e
a
c
d
11f
45
21
22
23
24
25
26
27
18
19 1317
3732 19a38 16b
14
16a
15
17a
GIM1329-070
GIM1329-065
8
Model 122 Regulators Installation and Maintenance Instructions
1. Disassemble diaphragm assembly per section “To Service
Main Diaphragm (11d)”.
2. Remove bolts 25 and lower diaphragm case 24.
3. Remove seal washer 12e, spacer 12a and gasket 26, and
remove seal diaphragm 12b.
4. During assembly use screwdriver in slot in top end of stem
12d or 12t while tightening nut 11a. Diaphragms must not be
twisted or strained during regulator reassembly.
1. Remove seal diaphragm 12b per section “To Service Seal
Diaphragm (12b)”.
On 1½" Model 122 remove bushing 41 (See Fig. 2) and 2" or
2½" Model 122 remove control tube.
2. Reinstall seal diaphragm 12b and gasket 26 so they cover
and block hole for and 41, and reassemble. On Back
Pressure Regulators and Relief Valves, install washers 12c
and 12e, spacer 12a, seal diaphragm 12b and two grip
washers in place of spacer 12s, and reassemble. Emery
surface of grip washers must face against both sides of
seal diaphragm 12b. Seal diaphragm 12b and gasket 26 must
block the hold for or 41. However, and 41 are not used
in the Back Pressure Regulators and Relief Valve.
3. Remove plug 24a and install external control line.
1. Remove seal diaphragm 12b per section “To Service Seal
Diaphragm (12b).”
2.
in place as shown in gure 2. Install bushing 41 and O-ring 42
(Figure 2). On 2" and 2½" Model 122 install control tube
and O-ring 42. Control tube must be centered and aligned
with slots faced downstream as shown.
GIM1329-065
GIM1329-070
(Internal Control)
3. Rotate seal diaphragm 12b and gasket 34 to match or 41
and reassemble.
On Back Pressure regulators and Relief Valves, install spacer
12s in place of spacer 12a, washer 12c and seal diaphragm
12b, and reassemble. Gasket 26 must cover opening for
or 41.
4. Install plug 24a.
Illustration
Number Description
Part
Number
9 Spring, See Tables, Pages 3–4
11a Hex S. Nut 908158
11b Diaphragm Plate 121-10-022-50
11c Diaphragm Pan 121-16-017-50
11d Diaphragm, Buna-N 121-16-150-50
11f Grip Washer 121-10-178-50
12a Spacer 121-42-079-01
12b Seal Diaphragm, Buna-N 121-42-064-00
12c Clamp Washer 121-42-010-00
12d Stem, Std. 121-42-016-00
12d Stem, Stainless 121-42-016-02
12f Seal Washer 107-62-358-01
12e Seal Washer (Emery Cloth) 121-10-179-50
12s Spacer, Stainless 121-42-079-03
1
2
3
9
45
21
22
23
24
25
26
27
21a
11
f
b
a
c
d
12
f
e
b
a
c
t
11f
16a 13
1514b 19 381816b 19a 37
14a
32
1
2
3
9
45
21
22
23
24
25
12
e
f
s
t
16a 13
1514b 19 381816b 19b 37 32
11
f
b
a
c
d
GIM1329-075
9
Model 122 Regulators Installation and Maintenance Instructions
(Continued)
Illustration
Number Description
Part
Number
12t Stem Stainless 121-42-016-03
13 O-ring ⅜" x ½" 934007
14 Wave Washer 905479
14a Valve Washer Ret. (B/P) 121-16-103-50
14b Valve Spacer Washer (B/P) 121-16-102-52
15 Valve, Buna-N 121-16-311-50
16a Retaining Ring, (5100-75H) 904447
16b Valve Holder 121-16-130-50
16b Valve holder (Stainless Steel) 121-16-130-51
17a Spring Holder 121-42-018-00
19 Orice, 25/32" dia., Std. 121-16-023-51
19 Orice, 25/32" dia., Stainless 121-16-023-52
26 Gasket 121-42-063-00
27 Valve Stem Bushing 121-42-373-00
32 Tetreseal (or O-ring), 3¼" x 3½" 904078
40 Control Tube 121-42-315-00
43 Control Tube 121-43-315-00
45
Travel Indicator
Repair Kit – consisting of Main and Seal
Diaphragms, Seal Washers, Molded Valve
with Wave Washer and Retaining Ring,
Tetraseals and Gaskets: All internal
control models except Back Pressure or
Relief (Std.)
Internal Control Back Pressure and Relief
All external control models (Std.)
091-00-365-65
121-42-598-00
121-42-598-02
121-42-598-01
Be certain the following section is clearly understood before using
the information.
The maximum inlet pressure a Model 122 regulator may be
subjected to under abnormal conditions without causing internal
damage is 20 psi.
The Maximum pressure the diaphragm may be subjected to
under abnormal conditions without causing internal damage is
set-point plus 2 psi. Set-point is dened as the outlet pressure a
regulator is adjusted to deliver.
If either of the above limits is exceeded the regulator must be
taken out of service and inspected. Damaged or otherwise
unsatisfactory parts must be repaired or replaced before returning
the regulator to service.
The maximum pressure that can be safely contained by the
diaphragm case on a Model 122 regulator is 5 psi. Safely
contained means no leakage as well as no bursting.
Protect the downstream piping system and the regulator’s low
pressure chambers against over-pressurization due to the
possible regulator malfunction or failure to achieve complete
lockup. The allowable outlet pressure is the lowest of the
maximum pressures permitted by federal codes, state codes,
Sensus Bulletin RDS-1498, or other applicable standards. The
method of protection can be a relief valve, monitor regulator,
shutoff device, or similar mechanism.
Capacity of the Model 122 in the wide-open position can be
calculated using the following formula and K factors:
1. Q = K√P0(P1– P0)
Q = Full open capacity in SCFH of 0.6 specic gravity
natural gas.
P0= absolute inlet pressure (psia)
P1= absolute outlet pressure (psia)
2. K Factors=
1" Model 122-8 K = 1400
1¼" Model 122-8 K = 1750
1½" Model 122-12 K = 2750
2" Model 122-12 K = 4750
2½" Model 122-12 K = 5250
Remember at the above full open capacities the droop is
signicantly greater than specied in the capacity tables.
When checking 122 regulator capacity to provide adequate relief
valve capacity, use the above calculated full open capacity.
Capacities for pressure reductions not listed in the table can be
calculated with the above formula.
GIM1329-075
A B C D E F
Shpg.
Wt.
1" NPT 10¼" 11⅝" 1⅞" 5¾" 2½" 37⁄16" 15 lbs.
1¼" NPT 10¼" 11⅝" 1⅞" 5¾" 2½" 37⁄16" 15 lbs.
1½" NPT 14" 13" 2⅜" 7½" 315⁄16" 39⁄16" 28 lbs.
2" NPT 14" 13" 2⅜" 7½" 315⁄16" 39⁄16" 28 lbs.
2½" NPT 14" 13" 2⅜" 8¼" 315⁄16" 39⁄16" 30 lbs.
Optional
Control Line
Connection
½" N.P.T.
A (Diameter)
B
C
D
E
F
Vent Outlet
¼" N.P.T.
*Taps must be
specied when
ordering.
805 Liberty Boulevard For more information, visit us at www.sensus.com/gas
DuBois, PA 15801
1-800-375-8875
All products purchased and services performed are subject to Sensus terms of sale, available at either: http://na.sensus.com/TC/TermsConditions.pdf or 1-800-METER-IT. Sensus reserves the right to modify
these terms and conditions in its own discretion without notice to the customer.
This document is for informational purposes only, and SENSUS MAKES NO EXPRESS WARRANTIES IN THIS DOCUMENT. FURTHERMORE, THERE ARE NO IMPLIED WARRANTIES, INCLUDING
WITHOUT LIMITATION, WARRANTIES AS TO FITNESS FOR A PARTICULAR PURPOSE AND MERCHANTABILITY. ANY USE OF THE PRODUCTS NOT SPECIFICALLY PERMITTED HEREIN IS
PROHIBITED.
IN-G-REG-13-29-0814-03-A
Model 122 Regulators
Installation and Maintenance Instructions
Body .......................................................................Cast Iron
Diaphragm Case .......................... .Die Cast Aluminum Alloy
Stem Bushing and Plate.................................... Plated Steel
Main and Seal Diaphragms ...............................Buna-N with
Nylon Fabric Insert
Orice ......................... Cast Iron (1½", 2" & 2½" Model 122)
Orice ................................. Brass (¾", 1" & 1¼" Model 122)
Valve.................Plated Steel with Molded Buna-N Soft Seat
Stem ..............................................................Stainless Steel
Diaphragm Pan, Collars & Washers.................. Plated Steel
O-rings and Tetra Seals............................................ Buna-N
Adjustment Spring Button........................... Zinc Die Casting
(1" through 2¾" Model 122)
Adjustment Spring Button.......................Thermo-Set Plastic
(¾" Model 122)
Seal Cap..........................Zinc Die Casting (1" through 2½")
Thermo-Plastic (¾" Model 122)
Model 122 Regulators are mainly used on natural gas.
However, they perform equally well on LP gas, nitrogen, dry CO2,
air and others.
Type of Gas Correction Factor
Air (Specic Gravity 1.0) 0.77
Propane (Specic Gravity 1.53) 0.63
1350 BTU Propane-Air Mix (Specic Gravity 1.20) 0.71
Nitrogen (Specic Gravity 0.97) 0.79
Dry Carbon Dioxide (Specic Gravity 1.52) 0.63
For other non-corrosive gases use the following formula:
0.60
CORRECTION FACTOR = √ Specic gravity of the gas
© 2014 Sensus
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